Re: [moderation/CI] Re: iomap: follow the alignment requirement for iomap_dio_hole_iter()

#syz upstream

On Sat, Aug 1, 2026 at 9:46=E2=80=AFPM syzbot ci
<[email protected]> wrote:
>
> syzbot ci has tested the following series
>
> [v2] iomap: follow the alignment requirement for iomap_dio_hole_iter()
> https://lore.kernel.org/all/9209e7204fc6b7b60c28f196750084be8a2faba8.1785=
[email protected]
> * [PATCH v2] iomap: follow the alignment requirement for iomap_dio_hole_i=
ter()
>
> and found the following issue:
> general protection fault in iomap_dio_hole_iter
>
> Full report is available here:
> https://ci.syzbot.org/series/9d98023b-4249-4697-ab21-ea7cf83805c8
>
> ***
>
> general protection fault in iomap_dio_hole_iter
>
> tree:      vfs
> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/vfs/v=
fs.git
> base:      fa20f6cb6063f7f1a6a56693d4a8713f19058d23
> arch:      amd64
> compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~e=
xp1~20260613092250.77), Debian LLD 22.1.8
> config:    https://ci.syzbot.org/builds/a53b891c-9ac3-484a-a77e-61c04d351=
57f/config
> syz repro: https://ci.syzbot.org/findings/8ed3b1e3-7e4e-4c2c-b0f6-934cfea=
6e536/syz_repro
>
> syz.0.17: attempt to access beyond end of device
> loop0: rw=3D2049, sector=3D53248, nr_sectors =3D 976 limit=3D40427
> Oops: general protection fault, probably for non-canonical address 0xdfff=
fc0000000003: 0000 [#1] SMP KASAN PTI
> KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
> CPU: 1 UID: 0 PID: 6257 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(f=
ull)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.=
16.2-1 04/01/2014
> RIP: 0010:bdev_get_queue include/linux/blkdev.h:1056 [inline]
> RIP: 0010:bdev_logical_block_size include/linux/blkdev.h:1401 [inline]
> RIP: 0010:iomap_dio_alignment fs/iomap/direct-io.c:412 [inline]
> RIP: 0010:iomap_dio_hole_iter+0x1bf/0x390 fs/iomap/direct-io.c:598
> Code: fc ff df 80 3c 08 00 74 08 4c 89 ef e8 aa d7 c7 ff 49 8b 6d 00 48 8=
3 c5 18 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74=
 08 48 89 ef e8 83 d7 c7 ff 41 bd 58 01 00 00 4c 03
> RSP: 0018:ffffc90003eff500 EFLAGS: 00010206
> RAX: 0000000000000003 RBX: ffffc90003eff680 RCX: dffffc0000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000000018 R08: ffff88816dc38fff R09: 0000000000000000
> R10: ffff88816dc38000 R11: ffffed102db87200 R12: 0000000000001000
> R13: ffffc90003eff6c8 R14: ffff88816b839c00 R15: 1ffff1102d707388
> FS:  00007ffb1678d6c0(0000) GS:ffff8882a8f4b000(0000) knlGS:0000000000000=
000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000563ae8dcd0a8 CR3: 0000000110cf4000 CR4: 00000000000006f0
> Call Trace:
>  <TASK>
>  iomap_dio_iter fs/iomap/direct-io.c:-1 [inline]
>  __iomap_dio_rw+0xe56/0x1ac0 fs/iomap/direct-io.c:823
>  f2fs_dio_read_iter fs/f2fs/file.c:4887 [inline]
>  f2fs_file_read_iter+0x60b/0x940 fs/f2fs/file.c:4950
>  copy_splice_read+0x5ff/0xaa0 fs/splice.c:362
>  do_splice_read fs/splice.c:979 [inline]
>  splice_direct_to_actor+0x4b6/0xcb0 fs/splice.c:1084
>  do_splice_direct_actor fs/splice.c:1202 [inline]
>  do_splice_direct+0x195/0x290 fs/splice.c:1228
>  do_sendfile+0x52e/0x7c0 fs/read_write.c:1371
>  __do_sys_sendfile64 fs/read_write.c:1432 [inline]
>  __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1418
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7ffb1599e019
> Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f=
7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff=
 ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffb1678d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
> RAX: ffffffffffffffda RBX: 00007ffb15c25fa0 RCX: 00007ffb1599e019
> RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004
> RBP: 00007ffb15a3500c R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000800000009 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007ffb15c26038 R14: 00007ffb15c25fa0 R15: 00007ffc15b4ab58
>  </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:bdev_get_queue include/linux/blkdev.h:1056 [inline]
> RIP: 0010:bdev_logical_block_size include/linux/blkdev.h:1401 [inline]
> RIP: 0010:iomap_dio_alignment fs/iomap/direct-io.c:412 [inline]
> RIP: 0010:iomap_dio_hole_iter+0x1bf/0x390 fs/iomap/direct-io.c:598
> Code: fc ff df 80 3c 08 00 74 08 4c 89 ef e8 aa d7 c7 ff 49 8b 6d 00 48 8=
3 c5 18 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74=
 08 48 89 ef e8 83 d7 c7 ff 41 bd 58 01 00 00 4c 03
> RSP: 0018:ffffc90003eff500 EFLAGS: 00010206
> RAX: 0000000000000003 RBX: ffffc90003eff680 RCX: dffffc0000000000
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000000018 R08: ffff88816dc38fff R09: 0000000000000000
> R10: ffff88816dc38000 R11: ffffed102db87200 R12: 0000000000001000
> R13: ffffc90003eff6c8 R14: ffff88816b839c00 R15: 1ffff1102d707388
> FS:  00007ffb1678d6c0(0000) GS:ffff8882a8f4b000(0000) knlGS:0000000000000=
000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000558d8b221b40 CR3: 0000000110cf4000 CR4: 00000000000006f0
> ----------------
> Code disassembly (best guess), 2 bytes skipped:
>    0:   df 80 3c 08 00 74       filds  0x7400083c(%rax)
>    6:   08 4c 89 ef             or     %cl,-0x11(%rcx,%rcx,4)
>    a:   e8 aa d7 c7 ff          call   0xffc7d7b9
>    f:   49 8b 6d 00             mov    0x0(%r13),%rbp
>   13:   48 83 c5 18             add    $0x18,%rbp
>   17:   48 89 e8                mov    %rbp,%rax
>   1a:   48 c1 e8 03             shr    $0x3,%rax
>   1e:   48 b9 00 00 00 00 00    movabs $0xdffffc0000000000,%rcx
>   25:   fc ff df
> * 28:   80 3c 08 00             cmpb   $0x0,(%rax,%rcx,1) <-- trapping in=
struction
>   2c:   74 08                   je     0x36
>   2e:   48 89 ef                mov    %rbp,%rdi
>   31:   e8 83 d7 c7 ff          call   0xffc7d7b9
>   36:   41 bd 58 01 00 00       mov    $0x158,%r13d
>   3c:   4c                      rex.WR
>   3d:   03                      .byte 0x3
>
>
> ***
>
> If these findings have caused you to resend the series or submit a
> separate fix, please add the following tag to your commit message:
>   Tested-by: [email protected]
>
> ---
> This report is generated by a bot. It may contain errors.
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>
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>
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>
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>
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>
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